Rectifier and method of making same



Sept, 4, 1945. M F. SKINKER RECTIFIER AND METHOD OF MAKING SAME Filed July 9, 1943 m J 1 W 9/ E M m E w W A W M Patented Se t. 4,

ammo: nncrrr'ma ANDMETHOD or mama sum Murray F. Skinker, Montolalr, N; 1., m. to Federal Telephone and Radio Corporation,

Newark, N. 1., a corporation of Delaware Application July 9, 1943, Serial No..494,036

7 Claims. (01. 175-366) My invention relates to current rectifying. devices and to a method of constructing the same.

Oneobject of the present invention is to provide a simple, compact rectifying apparatus of the selenium type which has a satisfactory for- I and 6 are sprung so as to contact each other at point 14 asshown.

Wire 8 is covered, particularly" about the contact point I, with selenium which has been applied in any suitable manner known to this art.

ward-reverse current ratio and a high operating Wire 5 is coated with one of the usual low meltemciency ing point counter-electrode alloys such, for ex- A further object of the invention is to provide ample, as a combination of cadmium, tin and a method of quickly and easily constructing a, film, although othersuitable alloys may be eniu rectifier utilizin a minimum number fi g g 10 A preferred form of apparatus for carrying out Conventional recmymgrdevices r the selenium applicant's novel method is illustrated in Fig. 3. type are used for carrying relatively heavy A source of current l5' and a .switch It in series rents and are formed f a plurality of steel mates are adapted to be connected across the terminals a g g 1113 .3" 12 223 25% 252th 532? W -12153535322; metallic se um. ese p cus manly range from about threegqwms or an inch to tvohlzesconnected across the terminals 12 and I3 of nearly five inches in diameter.

However, it is often desirable to rectify small g' ggg g s pg g: g i i g ggr g gggfi currents such as those employed in connection with meters or other indicating instruments. in that t ey are rigidly supported at The usual disc or plate construction is not suitmints and However the are able for this work because the mum pracm allowed to contact one another. Source of curcal size of such a device is still excessive in relaay and its figi g f g t tion to the amount of current which is required 3; the g y fi and to be rectified through wire 6. This flow of current will heat The present invention accordingly provides, in the wire to such a temperature as to cause the place or the above'menmoned m or plates selenium covering to under the desired tr atpair of specially-treated wires of small diameter men e wmch when jomed m the manner described pro- After a desired period of treatment, switch 18 vme samacmry rectification or relatively small is opened. Source of current I! and switch l8 curren a are then disconnected from terminals l2 and I3.

Wuoltlher o i t r a gg Wire 6 is sprung into contact with wire 5 as I g' g bgdim i f k g shown in Fig. 1, the twowires being preferably 5 32 g: m 9 positioned so that they are at substantially right oded in angles to each other at point of contact I. a perspe ve ex Source of current l5 and switch it are then section, of a preferred embodiment of the presconnected across terminals m and H of wire 5 ent invention r 40 and upon closing of the switch wire 5 will be 2 is a View line and heated. The current sources l5 and I! will be a circuit mum!!! of such value as to heat the wires 5 and s to net in which 9! the-Present the required temperatures, which may have diftion may be carried out. gerent vamw In Fig. 1 is shown'a box or container 3 formed This heating of wire I will melt the alloy with insulating material and 1min! Over In which the wire is coated. At point 14 the melted the 3 are small spring 5 and t will flow over the selenium coating of wire wire 5 Passes through and 15 suppm'ted by two 6. and the resulting structure will appear as adjoining walls 01 box 3 as shown at I and shown in Fig. 2. A thin barrier layer is formed and has W0 Outer terminal Forum I. and H between the alloy and the selenium in the usual respectively. manner including electroforming.

Wire 0 thro sh n i supported by That the structure of m. 2 will rectify elecwall of box 3 opposite to the e Wire trical currents is well known in the art. The as shown at 8, and has an outer terminal II. barrier layer formed between the alloy and the End II of wire 8 may be left unattached. Wires selenium results in a marked difference in resistance for currents flowing in the forward and reverse directions. Current will flow readily from the wire 5 to the selenium, but practically not at all from the selenium to the wire I.

When the heating of wire I has progressed for a desired period, switch it is opened, source of current I! and switch II are disconnected from terminals I and II, projecting end ll of wire is clipped off, and lid 4 placed on box 3. Leads I3 and It may then form the input and output terminals respectively of the completed rectifying device.

Care should be taken to keep the contact point it between the wires 5 and 6 as small as possible, as it has been found that within certain limits the rectifying efficiency of the device varies in proportion to the current density at the point of contact. This current density in turn depends directly on the contacting area.

While I have described above the principles of my invention in connection with a specific apparatus and a specific method, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention as set forth in the objects of my invention and the accompanying claims.

I claim:

1. The method of constructing a rectifier which include coating a first wire with selenium, coating a second wire with a counter-electrode alloy having a low melting point, passing current through the first wire to heat treat the selenium, placing the wires in contact with one another, and then passing current through the second wire to melt the alloy about the selenium at the Junction of said wires.

2. In a rectifier including a pair of resilient wires one of which is coated with selenium and the other of which is coated with a counterelectrode alloy having a low melting point, the method which comprises passing current through the selenium-coated wire to heat treat the selenium, placing the wires in contact with one another, and then passing current through the alloy-coated wire to melt the alloy about the selenium at the Junction of said wires.

3. In a rectifier, a pair of wires in contacting relation, a selenium coating on one of said wires. and a counter-electrode alloy coating on the other wire fused to the selenium coating at the region of contact.

4. In a rectifying apparatus, a container, a pair of wires partially enclosed in said container, one of said wires passing through and being supported by the wall of said container at two points, the other of said wires passing through and being supported by the wall of said container at a single point, said wires being in contacting relation within said container, a counter-electrode alloy coating on one of said wires, and a selenium coating on the other of said wires, said alloy ing fused to said selenium at the Junction of said wires.

5. A rectifying apparatus according to claim .4 in which said container is in the form of a box of insulating material, and each of said wires respectively passes through and is supported by an opposite wall of said box.

6. In a rectifying apparatus, a container of insulating material, a pair of wires supported within said container, said wires being in contacting relation, a counter-electrode alloy coating on one of said wires, and a selenium coating on the other of said wires, said alloy being fused to said selenium at the Junction of said wires.

7. A method of constructing a selenium rectifier which comprises coating a wire with a counter-electrode alloy, coating a conductor with selenium, applying the alloy to the selenium surface and fusing the alloy to the selenium surface by heating the wire by means of a current passed through it, thereby melting the alloy, and then cutting off the current and allowing the alloy to cool in fused relation to the wire and. the selenium surface.

MURRAY F. 

